This application claims priority from German Application No. 10052071.5, filed on Oct. 19, 2000, and German Application No. 10107579.0, filed Feb. 17, 2001.
The invention relates firstly to a pressing tool for pressing pipe ends, in particular ends of pipes laid for sanitary purposes, having pressing jaws which are connected to one another in an articulated manner, it being the case that a pressing jaw has a pressing insert, and has a circle-segment-like configuration in the region of interaction between the pressing jaws and the pressing insert, and the pressing insert can be moved in the circle-circumference direction relative to the pressing jaw, and it also being the case that, during a pressing operation, the pressing inserts come into abutment in first instance at mutually facing first ends, while a movement gap still remains at second ends.
Such pressing tools for pressing pipe ends or the like are known.
In respect of the above-described prior art, it is a technical problem of the invention to develop advantageously a pressing tool of the type in question.
This problem is solved first and foremost by the subject matter of claim 1, this being based on the fact that the pressing tool has two pressing jaws, which supplement one another to form a closed pressing geometry, and that the abutment location of the pressing inserts and the movement gap are formed opposite one another, preferably diametrically opposite one another. This configuration provides a pressing tool which, by means of two pressing jaws, is also suitable for pressing pipe ends of relatively large diameter. This is achieved by the pressing inserts being secured in a floating manner in the two pressing jaws since, as a result, the pressing inserts can be moved in circle-circumference direction relative to the associated pressing jaws. During the pressing operation, the mutually facing first ends of the pressing inserts come into abutment, while, opposite this abutment location, the movement gap forms between the second ends. A preferred arrangement of two pressing inserts provides that the abutment location of the pressing inserts and the movement gap are aligned diametrically opposite one another on an axis of symmetry of the pressing jaws, which supplement one another to form a closed pressing geometry. It is also preferred for the movement gap to form between the second ends of the pressing inserts of a pressing-tool articulation formation connecting the pressing jaws. Correspondingly, those ends of the pressing inserts which are located opposite the articulation come into abutment. Alternatively, however, it is also possible for the inserts to abut in the region of the articulation formation, in which case the movement gap then remains opposite this articulation formation. It is also preferred for each pressing jaw to be assigned a pressing insert which can be moved in the circle-circumference direction. A pressing implement, for example a hydraulic pressing implement, advantageously acts on the pressing-jaw free ends, which are located opposite the articulation formation, the pressing inserts, further preferably, being secured in the pressing jaws, in an unloaded basic position, such that they project beyond the free end surfaces of the pressing jaws by way of their first, mutually facing ends, so that these free ends come into abutment first during the pressing operation. As the pressing operation progresses, the pressing inserts, which are supported on one another in the region of the first ends, move relative to the pressing jaws, which results in the movement gap, which is located opposite the abutment location, being closed.
The invention also relates to a pressing tool for pressing pipe ends, in particular ends of pipes laid for sanitary purposes, having pressing jaws which are connected to one another in an articulated manner, it being the case that a pressing jaw has a pressing insert, and is of circle-segment-like configuration in the region of interaction between the pressing jaw and the pressing insert. In order for a pressing tool of the type in question to be developed advantageously, it is proposed that the pressing inserts are secured by latching in an operationally releasable manner. It is thus advantageously possible for the pressing inserts to be released from the pressing jaws extremely easily, if appropriate, without any tools, but at least without any special tools, it further being possible for each pressing insert to be exchanged individually. It proves to be particularly advantageous here that the pressing inserts can be released without the latching securing means being dismantled and, furthermore, also without the latching elements being released, for example unscrewed. This configuration according to the invention makes it possible for the pressing inserts to be changed extremely easily, preferably without the use of tools. In this respect, it is further proposed that provided for securing purposes are two pins which, oriented radially inward on a pressing jaw and on a radial line, project inward beyond the pressing jaw, are spaced apart from one another in the direction of the circle, engage in associated bores of the pressing inserts, and of which at least one can be moved out of the pressing insert for removal of the same. The pressing insert can be moved out in the radial direction, for example, by means of a handle which is connected to a first pin. Furthermore, hand-actuated pivoting of the first pin out of the latching securing means is also conceivable. In addition, a preferred configuration of the subject matter of the invention provides that, in the case of a pressing tool with two pressing jaws, which supplement one another to form a closed pressing geometry, the two pins arranged in each pressing jaw each enclose an acute angle in relation to the associated end side directed towards the end side of the other pressing jaw, so, further preferably, an angle of 15-45xc2x0. It also proves to be particularly advantageous that this securing means according to the invention can serve both for the latching accommodation of a fixed pressing insert and for the latching accommodation of a floating pressing insert, i.e. one which can be moved in the circle-circumference direction relative to the pressing jaw, for which purpose, if the latter are used, these have bores for the latching pins which allow the desired capacity for movement, for example bores, the diameters of which are greater than, for example double the size of, the pin diameter, or slot-like bores. The above-described features prove to be advantageous both individually and in combination. It is thus further proposed that the movement gap first of all remains in the region of an articulation connection of the pressing jaws, i.e. opposite the side on which the pressing tool acts on the pressing jaws. It is alternatively proposed, in this respect, that the movement gap first of all remains in the region of the unconnected ends of the pressing jaws, i.e. in the region where the pressing tool acts on the pressing jaws. The pressing jaws may be formed here as pressing members which can be released, at least in part, from the pressing tool. In this respect, it is further alternatively proposed that the pressing jaws are formed in mouth sections of the tong legs of the pressing tool. As a result, single-piece configuration of the pressing jaws and tong legs is selected, which pressing jaws are formed for accommodating pressing inserts. The tong legs of the pressing tool are usually connected in an articulated manner by means of link plates. In this respect, it is proposed, in a development of the subject matter of the invention, that the first pin, which can be moved out of the pressing insert, is disposed in the mouth opening remote from the link plates. Alternatively, it is also possible for this first pin, which effects the release of the pressing insert, to be disposed in that end region of the pressing jaw which is directed towards the link plates. It is also proposed that a second pin, which cannot be moved out, is disposed in the region of the link plates, it also being possible for this second pin, according to the above-described alternative, to be positioned in that region of the pressing jaw which is remote from the link plates. It is additionally provided that the second pin, which cannot be moved out, is secured for rotary articulation in the pressing jaw, the longitudinal axis of the pin sassing through the rotary articulation. In the closed position, i.e. in the pressing position, the rotary-articulation axis preferably extends parallel to the pressing-mouth axis formed in the region of the pressing jaws and/or of the pressing inserts. In order to ensure the specified rocking mounting of the insert which is to be accommodated in the pressing jaw, it is provided that the second pin passes through a circumferentially extending slot of the pressing jaw. In this respect, it is also proposed that the second pin is spring-prestressed against one end of the slot. For removing the pressing insert from the pressing jaw, the first pin can be moved out of the associated bore or engagement opening of the pressing insert. For this purpose, the first pin may have a handle, for displacing the first pin in the axial direction counter to a spring force, thus, for example, by the first pin being displaced back with pulling action in the radial direction, in relation to the pressing-insert extent. Alternatively, it is proposed that the first pin is formed on a rocker, which rocker is formed as a handle. In this respect, it is further proposed that that end of the rocker which is directed away from the first pin is spring-supported in the pressing jaw, for automatically displacing the first pin back into the engagement position.
The invention also relates to a pressing insert for a pressing jaw of a pressing tool for pressing pipe ends, it being the case that the pressing insert is of a circle-segment-like configuration. In order to develop advantageously such a pressing insert as far as its properties are concerned during the pressing operation, it is proposed that the pressing insert, on the inside, has a section of first curvature and a tongue-like section of second curvature which, in the unloaded state, projects inwards, at its end in any case, beyond the section of first curvature. This configuration according to the invention gives pressing inserts which make it possible, using a pressing tool with two pressing jaws and two associated pressing inserts, to carry out pressing operations with nominal widths of over 50. For the purpose of carrying out pressing operations with nominal widths of over 50, the prior art includes pressing tools which have three or more pressing jaws and/or pressing inserts. Furthermore, the configuration of the pressing insert according to the invention gives the advantageous effect that, during the pressing operation, the tongue-like section of second curvature, upon reaching a pressing force of, for example, 500 kg, is displaced into the deflected position following the first curvature, and that, when the action of force is released, the spring-back of the tongue-like section of second curvature causes the pressing insert to lift off from the blank.
The invention also relates to a pressing insert for a pressing jaw of a pressing tool for pressing pipe ends, it being the case that the pressing insert is of circle-segment-like configuration. In order to develop advantageously here, in particular in handling terms, a pressing insert of the type in question, it is proposed that the pressing insert has two engagement openings which are offset over the circumference and are intended for securing pins. As a result of this configuration according to the invention, the pressing insert can be secured by latching, in pressing jaws of a pressing tool, in an operationally releasable manner. The above-described features of the pressing insert according to the invention are advantageous both individually and in combination. An advantageous development of the subject matter of the invention thus provides that the tongue-like section of second curvature is cut out of the section of first curvature, the tongue tip, furthermore, being disposed eccentrically in relation to a circumferential extent of the pressing insert. Furthermore, the tongue-like section has a width which is less than the width of the pressing insert. As a further alternative, or in combination with the above-described solution, it may be provided that the pressing insert has two engagement openings which are offset over the width and are intended for securing pins. A preferred configuration here is one in which the engagement openings are formed mirror-symmetrically in relation to a circumference bisector. The engagement openings may be in the form of bores or slot-like bores. It is preferred here, however, for one or both of the engagement openings to be blind bores.